His old club heaped the misery on the Latics with a 1-0 win that keeps them deep in relegation trouble, and closer to playing League One football next season, as they now remain nine points adrift of safety. With 13 games remaining, it will take some turnaround in fortunes for them not to slip down another division.
The build-up to the match had a lot of coverage over several board members missing because of the appointment of Mackay - who was found to send offensive text messages regarding race and sexism during his time in the Welsh capital - and the subsequent comments from Wigan chairman Dave Whelan about Jewish and Chinese people.
In terms of the game itself, it was settled by an Aron Gunnarsson strike midway through the first half to give Russell Slade's side the win which moves them up to 13th in the Championship table.
There may have not been much in the tie and Mackay will probably take a few positives from the game, which saw Jermaine Pennant make his debut for the club, but at the end of the day it's another blow for a Wigan side that has only won twice in the league under their manager.
Here is a selection of images from last night's action in Wigan: